Treating tobacco in hogsheads



Patented Apr. 19,49 v I I i I v Q UNITED STATES TPATENT OFFICE TREATING ToBAcco iN HoGsHEnn John M. Baer, Chicago, 111., assignor to The -GuarditeCo -poration, Chicago, ilL, a corpora- 'tion of Illinois No Drawing. Application nprnz'z, 1939, Serial N0.'270,461

Claims. (C1.181;55)

Thisinvention relates to a process of increas \vas sprayed-in'with the first steamingoperation.

ing the. hydrophilic character of tobacco in hogs- The operation was stopped at the point described heads and is a continuationin-part of mycoand it was found that,as expected, the cold spot pending applications Serial No. 155,776 filed July had not been'completely eliminated.

5 26, 1937, and Serial No. 167,858 filed October Iii-another operation Kentucky burleytobacco 5 7, 1937. in'a 'hogshead showed a temperature of 785 F.

Tobacco is a very peculiar material and the six inchesirom the outside, and'of"82 F. atthe problem of moistening it, particularly in large center. The hogshead was evacuateduntil the compressed bulk such as in hogsheads, is an center thermometer showed 70 F. and theout involved and intricate one. With most sub side 715 F. A first steaming and'spraying oper- -10 stances it is suificient to remove all air from the ation was then'carried out, the outer bulb going material, after which any steam introduced will to 160 F. and the inner bulb to only 80 F. A penetrate at once throughout the product and relatively heavy evacuation was carried out durmoisten it. In the case of tobacco, particularly 1 ing which :the center bulb rose to 88 F., while the 35 when so packed, even when all of the air has been outer one fell to 102 F. During this cycle the removed from the tobacco, cold spots will sometobacco in the cold spot became hydrophilic. times occur in the tobacco upon the subsequent Upon e n S e Operation b bulbs steaming. Sometimes these cold spots are quite rose toapproximately 156 F.

' extensive in size and they may be at the center In another operation a hogshead of Kentucky 39 of the hogshead, on the very edge, or at practi-' burley tobacco showed a temperature near the I cally any point throughout it. 2 outside of .82? F., and at the center of 78 F. A These cold spots appear to be due to the hydro vacuum was pulled until the-center temperature phobic character of tobacco under certain conhad dropped to 70 F. Thereupon, steam was ditions, When the spray process of the Bailey introduced until. the outer temperature had application, Serial 205,652, filed May 2, 1938, reached 160 F. At this time the center tcmis employed, the cold spots show that the tobacco perature was only 80F. A vacuum was then is hydrophobic also to liquid water. In many inpulled until the outer temperature had dropped stances this hydrophobic character will prevail to 91 F. duringwhich time thecenter temperathrough several steaming and evacuation cycles. ture rose to 95 F. Again the tobacco became In processes such as those described in my hydrophilic so that upon a second steaming oper- -30 copending applications referred to above, it has mm in which the outer temperature rose to been found that a thermometer in the center of I 161 F., the inner temperature rose to 160 F. v a cold spot will frequently show no increase in In another operation upon Kentucky burley temperature upon steaming but will show an in-- tobacco the center temperature remained-at 68 crease in temperature upon a subsequent deep F. upon'steaming following evacuation, whereas evacuation cycle. I the outertemperature went to 161 F. Upon For example, a hogshead of Kentucky burley evacuating again, the outer'temperature was retobacco having an initial temperature of 90.5? F. duced to 75 while the inner temperature rose to was subjected to a vacuum until the temperature p n a second steaming the outside temhad'dropped to 82 F., whereupon steam was in- 'perature was carried to 165, whereas the inner 4U troduced to bring the bulk of the tobacco to temperature ,went only to 87 F. The tobacco. 157 F.. A bulb in the center of a cold spot, howwas still hydrophobic and upon third evacuation everfremained at approximately 82 F., in fact the outer temperature was reduced to 124 while actually indicating 805 F. at the termination of the inner temperature rose to 96. This 'markthe steaming operation. Thereupon the tobacco edly increased the hydrophilic character of the tion the temperature in the cold spot rose to in accordance with the Bailey application, was

was subjected to an increased vacuum w th its tobacco in the cold spot and on a thirdsteaming temperature had dropped to 117 F. in those por- 7 cycle the outer te p Was ed to 64 tions which had shown the temperature increase and the inner temperature went to F. In uponv steaming. During this evacuation operathe first two steaming operations water. spray,

91 F. Somewhere in this range the tobacco beemp yed. came hydrophilic so that upon a second steaming While'th'e most hydrophobic tobacco generally operation, the bulk of the tobacco was steamed ppea s n ar he Center Of the hogshad, this is to 160 ,F. and the temperature in the cold spot not always the case. One reason why it appears 5 rose to F. In the cycle just described, water more frequ is p s h when a ther- 55 mometer is inserted only six inches from the outside it tends to provide a pathway along which the steam can go. The thermometer then becomes heated and transfers Warmth to the surrounding tobacco so that there is a general tendency in this manner to render adjacent tobacco hydrophilic. Thus, the frequency of observing exterior cold spots with a thermometer is far less than the actual occurrence of such phenomena. It may also be that the center of the hogshead becomes hotter during fermentation processes in storage and. that in this way it becomes more hydrophobic.

The paradoxical rise in temperature during the evacuation cycle would appear to be due to the passage of steam boiled from the hotter portions of the tobacco through the colder portions. It would appear that when the tobacco has been heated to approximately 90-100 F., even the most hydrophobic material requires an increased ability to pick up moisture; but many hydrophobic tobaccos retain some of their hydrophobic characteristics above this range. It is somewhat diflicult to give a specific hydrophobic limit because tobaccos differ so widely. At about 110 F. to 125 F., however, the temperature seems to change the tobacco to such an extent that it is markedly hydrophilic in substantially all cases.

The reasons for the development of hydrophilic characteristics are not at all understood. It is a fact that as tobacco is heated, even without an increase in moisture content, its pliability increases. This indicates, of course, that water in chemical combination has been driven out of the combined form and has become available as water. The same phenomenon is familiar in the case of other organic products such as bread, which become apparently much wetter upon heating.

The more pliable tobacco becomes, the more hydrophilic it appears to become. Therefore, the

repetition of the cycles is not only important in making the tobacco receptive to steam but is even more important in connection with the spray process described in the Bailey application. In connection with that process it has been found highly desirable to steam the tobacco before spraying it. This is true, surprisingly enough, even though the tobacco is then reduced almost to the temperature which it originally had, inasmuch as some of the hydrophilicness appears to be retained for a short while after cooling.

In accordance with this invention, therefore, tobacco in hogsheads is treated by a cycle of operations which are sufficient to insure that for the particular kind of tobacco all portions will not only have become hydrophilic, but that ample opportunity shall have been afiorded for it to receive its due proportion of water either as steam or in liquid form, or from both sources. For the darker tobacco, such as Kentucky burley, with which a temperature of to F. may be employed with safety, an operating procedure consisting of five cycles is satisfactory to carry out the regular processing of a factory. Such a process may be carried out day after day without the occurrence of any substantial'amount of cold and dry tobacco.

Where bright tobaccos are treated, a procedure consisting of five cycles is likewise satisfactory where temperature ranges to say about 140 F. top can be employed. Where, however, the maximum temperature permitted at any time is say 120 F. it is frequently found necessary to increase the number of cycles.

It has been discovered that by following a very simple formula, the steaming and evacuating steps may be regulated so that under all normal conditions tobacco of whatever usual type may be treated without the occurrence of any substantial number of cold spots.

These formulae are applicable regardless of the maximum temperature to which the tobacco is subjected.

These formulae are as follows:

A B=at least 20 C D=at least 50 Preferably the product of A and B should be at least 30, and the product of C and D at least 64.

For example, leaf tobacco was controlled by a pressure control; the absolute pressure being dropped initially to approximately 0.22 inch; steam and water spray being introduced to bring the pressure to 4.4 inches; 2. pressure of 1.30 then being produced by evacuation; steam being admitted to bring the pressure to 5.7 inches; the vacuum being again increased until the pressure had dropped to 1.60 inches; steam being admitted to bring the pressure to 5.90 inches; the pressure then being dropped to 2.40 inches; steam being admitted to bring it back up to 6 inches; pressure then being dropped to 2.40 inches again; and

finally being brought back up by steam to 6 inches.

In this operation there were four evacuation cycles following steaming cycles with a total evacuation of 14.3 inches, so that the product of A and B was 57.2 or well above the minimum for I proper treatment. At the same time the total steaming represented 20.1 inches and there were five steps, so that the product was 100.5, again leaving a considerable margin of safety. However, if the process had been stopped at the I end of the third steaming, the products of A and B and of C and D would both have been too low.

In another operation in which higher temperatures and pressures were employed, an absolute pressure of 0.2 inch was produced followed by steaming to 4 inches. The pressure was then decreased to 0.4 inch, increased to 8 inches, de-

creased to 1.2 inches, increased to 8 inches, de-

creased to 1.4 inches and finally increased to 8.0 inches. Here again the product of A and B was well above 20, and the product of C and D was well above 50; but in both cases, if the final step had been omitted, the product would have been below that stated in the formula.

In an intermediate case, a vacuum of 0.25 inch of absolute pressure was produced; steam admitted to bring it to 3.6 inches; the pressure lowered to 1 inch, raised to 7 inches, lowered to 2.6 inches, raised to 6.8 inches, lowered to 2.6 inches, raised to 7 inches, lowered to 2.7 inches, and raised to 4.6 inches.

It is preferred that in the treatment there shall be at least two evacuations to an absolute pressure below 1.5 inches, and preferably to 1 inch or below. This is particularly true when employing a water spray which is largely ineffective above 1 inch, even'with hot water.

What I claim as new, and desire to secure by Letters Patent, is:

cordance withthe following formulae:

A B=at least 20 C D=at least 50 where A is greater than 1 and represents the number of evacuation steps following a steaming step in which the absolute pressure falls at least as low" as 4 inches, B represents the total inches of evacuation during such evacuations, C is great- .er than 2 and represents the number of steaming steps following evacuations to at least l inches absolute, and D is, the total inches increase in pressure during such steaming steps.

2. The method asset forth in claim 1; in which the product of A and Bis at least 30 and the product of C and D is at least 64.

3. The method as set forth in claim l,'in which the absolute pressure is reduced as low as 1.5 inches of mercury at least twice 4. The method as set forth in claim 1, in which the absolute pressure is reduced as low as-l inch of mercury at least twice. I 5. The method as set forth in claim 1; in which a micromis't of Water is introduced in an atmos-' phere of steam at increased pressure after completion of successive steaming and evacuation cycles in accordance with the formulae of claim 1. 30

JOHN M. BAERF 

